GitBook, one of the most widely used platforms for technical documentation across product teams and engineering orgs, has taken a notable step: it has open-sourced the code it uses to render published GitBook content. In plain terms, this isn’t “GitBook going fully open source,” but rather the part that turns a published space into a fast, navigable documentation website with GitBook’s familiar look and behavior.
That component — available in the public GitbookIO/gitbook repository — is described as “the open source frontend for GitBook doc sites,” and it comes with a clear warning: while self-hosting is possible, GitBook doesn’t recommend it unless you’re sure it fits your needs. The subtext is straightforward: most teams are better off using the managed product (or contributing upstream) than running and maintaining a long-lived fork.
What GitBook actually open-sourced
The repository contains the renderer used for GitBook’s published sites. That distinction matters: the value here is in the “rendering layer,” not the full editing product or the entire SaaS platform. Still, for developers and documentation owners, this is significant because it unlocks practical use cases: embedding GitBook-published docs more tightly into an app, customizing the UI and theming, or experimenting with changes without waiting for platform updates.
The project also looks far from experimental. On GitHub, it shows strong adoption signals, with tens of thousands of stars, thousands of forks, and an actively maintained codebase. The stack is modern too: GitHub’s language breakdown shows TypeScript as the dominant language.
A modern stack: Next.js, Bun, and local development against any published GitBook
Technically, GitBook explains that the renderer is built on Next.js, and it lists very specific prerequisites for local development:
- Node.js version ≥ 22.3
- Bun version ≥ 1.2.15
Bun isn’t optional in this setup: GitBook notes it uses a text-based lockfile that older Bun versions can’t handle. The workflow is the familiar front-end loop: install dependencies with Bun and start the dev server with bun dev.
One particularly developer-friendly detail is how you can test the renderer locally. You can open any published GitBook site by prefixing its URL with http://localhost:3000/url/…. That means you can validate changes immediately against real public content — even if you don’t have your own GitBook space ready.
Contributing comes with some “CI reality”: icons, dependencies, and a boundary for outsiders
GitBook also highlights a common pain point in design-heavy projects: differences between local dev and CI. The project uses Font Awesome. Locally, you’ll typically get the free version, but GitBook states that CI only accepts the Pro package. If dependency changes accidentally persist the free version into the lockfile, contributors may hit a CI failure.
GitBook’s guidance draws a clear line: GitBook staff may need to help unblock these situations, often involving an internal NPM token set in .env.local via BUN_NPM_TOKEN before reinstalling dependencies. For external contributors, the takeaway is simple: if CI fails due to missing GitBook icons, it likely needs coordination with the GitBook team.
That said, the repo explicitly encourages contributions in accessible areas such as UI translations (stored under packages/gitbook/src/intl/translations), bug fixes, and incremental improvements. It also notes that pull requests are tested with visual and performance checks to prevent regressions — a strong signal that the renderer is treated as production-critical.
Self-hosting the renderer: real benefits, but full operational responsibility
The bluntest section of the README is about deployment: yes, you can self-host, but GitBook warns against it unless you’re confident it’s the right choice. The reason isn’t technical — it’s operational. If you self-host, you own uptime, maintenance, and the ongoing work of keeping your fork aligned with changes on the GitBook platform.
GitBook frames the tradeoff clearly:
- Pros: deeper customization of look and feel, and easier embedding of docs inside your product.
- Cons: you become responsible for reliability and for staying current as GitBook evolves.
Licensing is also a key consideration. The repository is distributed under GNU GPLv3. GitBook explicitly notes that if you plan to distribute the code, you must keep the source code public to comply with GPLv3. If you need to work privately in a distributed context, GitBook points to the option of a commercial license.
A return to open-source roots — without open-sourcing everything
GitBook positions this move as a partial return to its open-source origins: opening up the rendering engine makes the public-facing experience more transparent and more collaborative. It does not, at least right now, signal a plan to open-source the entire GitBook product — but it does meaningfully expand what teams can do with published GitBook content.
FAQ
Which part of GitBook is open source: the editor or the publishing renderer?
The open-source release covers the renderer for published GitBook sites (the frontend), not the full editor or the entire SaaS platform.
Can GitBook Open be self-hosted for internal documentation behind an intranet?
Self-hosting is possible, but GitBook doesn’t recommend it unless you have a strong reason, because it shifts maintenance and reliability to your team.
What does GPLv3 mean if a company modifies the code and distributes it?
Under GPLv3 (and as stated in the repo), distributing modified versions generally requires making the source code public; GitBook points to a commercial license for certain private distribution scenarios.
What are the local development requirements for GitBook Open?
GitBook lists Node.js ≥ 22.3 and Bun ≥ 1.2.15, and supports testing against any published GitBook URL via http://localhost:3000/url/....